Automatic machinery is used in modern bottling facilities for filling containers with gaseous liquids containing carbon dioxide and similar carbonations under counter-pressure which enables predetermined quantities of liquid to be delivered into the containers. This machinery comprises mechanisms for handling the containers in which the empty containers are raised until the neck engages the filling device in order to receive a predetermined volume of liquid at which time the containers are lowered and directed toward the capping machine. The filling machinery includes a reservoir containing a liquid which flows under the effect of gravity. The gas above the liquid maintains the carbon dioxide in the liquid and is used to charge the container. A filling valve is located in the reservoir and extends through the tank. The valve connects the reservoir with the empty container and opens to allow the container to be filled with liquid.
When the container is engaged in the filling device, the gas valve fills the container with a counter pressure gas. The bottle is then filled with liquid by opening the filling valve. During filling, the gas contained in the container is evacuated through a vent tube towards a gas chamber in the tank. As soon as the level of liquid in the container reaches the aperture of the vent tube, the gas, which is located in the neck of the container, can no longer escape and the flow is stopped. The liquid and gas valves are then closed. A snifter is operated to release the remaining pressure in the container.
The valves are generally controlled by synchronized cams actuating so that the gas is first admitted to the container, filling the container against counter-pressurizing gas until the pressure of the gas and the liquid are equal. A second valve is then opened allowing the liquid to flow into the container under the influence of gravity and under a pressure head. When the container is filled, the cam actuator closes the valve and the container is lowered for capping. The pressure in the neck of the container may be controllably released by a snifter valve and the container quickly capped and crowned.
One prior art filling valve used with a carbonated liquid bottling machine is disclosed in U.S. Pat. No. 4,089,353 to Antonelli in which a filling valve is shown which connects a container to be filled with a tank containing supply of liquid with which the container is to be filled and pressurized gas. A cylindrical seal seals the valve stem passageway. In the Meyer U.S. Pat. No. 3,500,879 a counter pressure type filler valve for introducing liquids into containers from a is provided with a swirl inducing member. A solid cap closes the valve stem passageway. Another typical control valve for filling containers with liquid under gaseous pressure from a reservoir is disclosed in U.S. Pat. No. 3,385,327 to Granier. The Fernades U.S. Pat. No. 4,086,943 shows a valve for filling containers with pressurized drinks. This patent is a typical back pressure filling valve for containers and provides an auxiliary passage for air and gas and a frusto-conical check valve for an elastomeric material to control the passage therethrough. The Dichiara U.S. Pat. No. 4,349,055 is for a filling valve for beverage container filling machines and is a cam operated valve having a screen filter mounted herein along with an auxiliary opening for the feeding of the liquid therethrough. A ball provides a seal against the valve stem passageway. The Kaiser U.S. Pat. No. 3,633,635 is for a filling element for counter pressure filling machines and includes a vessel or container for liquid and gas positioned beside the valve. The Yun U.S. Pat. No. 4,442,873 discloses a liquid filling valve for filling containers with carbonated liquid which has concentric valves for introduction of counter-pressure gas and liquid into the container.
The problem with these types of assemblies is that the planar charging caps are not pressure equalized by providing an aperture through the surrounding cap. Furthermore, sharp angles and component obstructions create turbulence which separates and releases absorbed gas from the liquid and therefore foam in the bottle. The position of the screen in the high pressure area also produces additional foaming. Additionally, the screen position further restricts the flow.